In recent years, a wireless LAN (IEEE802.11 standard) is becoming widespread and a large-scale wireless LAN network system is being constructed in a public network and corporate network. Along with this, there are studies on a shift from a method of setting up access points (AP), for example, wireless LAN base station apparatuses individually, to a method whereby an AP control apparatus is connected to a plurality of wireless LAN base station apparatuses and this AP control apparatus, for example, a wireless LAN base station control apparatus carries out automatic settings, fault management and collection of statistical information or the like of the wireless LAN base station apparatuses collectively. These studies are underway by IETF (Internet Engineering Task Force) which is a global standardization organization and the IEEE802.11 working group or the like and this standardization is now being developed.
Consequently, there is a study on an architecture whereby bridge processing between a wireless LAN frame (802.11 standard) and an Ethernet (registered trademark) frame is carried out by not a wireless LAN base station apparatus, but a host AP control apparatus and a point where authentication ports are opened/closed is also transferred from a wireless LAN base station apparatus to an AP control apparatus. Concerning such architecture, in an IETF CAPWAP working group, an LWAPP (light weight access protocol) is proposed as one of protocols which manage APs. Under this LWAPP, an AP control apparatus performs control such as an automatic setting of setting information, fault management, collection of statistical information, setting of encryption key information on a wireless LAN base station apparatus or the like.
The communication systems proposed here define a communication using an Ethernet (registered trademark) tunnel between the AP control apparatus and the wireless LAN base station apparatus to perform such control (see Non-Patent Document 1). This Ethernet (registered trademark) tunnel is determined by a set of a sender MAC address and a destination MAC address. The LWAPP describes that the MAC address of the sender interface is set at the sender MAC address of the Ethernet (registered trademark) tunnel and the MAC address of the destination interface is set at the destination MAC address. Furthermore, when a plurality of MAC addresses are given to the sender interface, it depends on the implemention which MAC address is set.
In conventional communication systems, one MAC address is set for one interface of the AP control apparatus and the wireless LAN base station apparatus or the like and communications are carried out using the MAC address of this interface. Therefore, communications are carried out between the AP control apparatus and the wireless LAN base station apparatus using one data tunnel (for example, Ethernet (registered trademark) tunnels).
As a result, control frames which are exchanged between the AP control apparatus and the wireless LAN base station apparatus and data frames other than the control frames are handled by identical data tunnel.
Non-Patent Document 1: IETF draft draft-ohara-capwap-lwapp-00.txt “Light Weight Access Point Protocol”